The U.S. Department of Defense said on Tuesday evening that Anthropic poses an “unacceptable risk to national security,” marking the agency’s first rebuttal to the AI lab’s lawsuits challenging Defense Secretary Pete Hegseth’s decision last month to label the company a supply chain risk. As part of its complaints, Anthropic had requested the court temporarily block the DOD from enforcing its label.

The crux of the DOD’s argument, made in a 40-page filing in a California federal court, is the concern that Anthropic might “attempt to disable its technology or preemptively alter the behavior of its model” before or during “warfighting operations” if the company “feels that its corporate ‘red lines’ are being crossed.”

Anthropic last summer signed a $200 million contract with the Pentagon to deploy its technology within classified systems. In later negotiations over the terms of the contract, Anthropic said it did not want its AI systems to be used for mass surveillance of Americans, and that the technology wasn’t ready for use in targeting or firing decisions of lethal weapons. The Pentagon contested that a private company shouldn’t dictate how the military uses technology.

Many organizations have spoken out against the DOD’s treatment of Anthropic, arguing that the department could have just ended its contract. Several tech companies and employees — including from OpenAI, Google, and Microsoft — as well as legal rights groups have filed amicus briefs in support of Anthropic. 

In its lawsuits, Anthropic accused the DOD of infringing on its First Amendment rights and punishing the company based on ideological grounds.  

A hearing on Anthropic’s request for a preliminary injunction is set for next Tuesday.

Anthropic did not immediately respond to a request for comment.